Electroluminescent display device and method of manufacturing the same

ABSTRACT

Disclosed are an electroluminescent display device and a method of manufacturing the same. The electroluminescent display device includes a first bank on a substrate, an anode electrode extending to one side and another side of the first bank in an area exposed by the first bank, a second bank on each of one side and another side of the anode electrode, a light emitting layer on an upper surface of the anode electrode exposed by the second bank, and a cathode electrode on the light emitting layer. Since the anode electrode is provided on the first bank, the anode electrode is prevented from being damaged in a process of patterning the first bank.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the Korean Patent Application No.10-2016-0181792 filed on Dec. 29, 2016, which is hereby incorporated byreference as if fully set forth herein.

BACKGROUND Technical Field

The present disclosure relates to a display device, and moreparticularly, to an electroluminescent display device and a method ofmanufacturing the same.

Description of the Related Art

Electroluminescent display devices are devices which have a structurewhere a light emitting layer is provided between two electrodes, andthus, emit light with an electric field between the two electrodes todisplay an image.

The light emitting layer may be formed of an organic material whichemits light when an exciton generated by a combination of an electronand a hole is shifted from an excited state to a ground state.Alternatively, the light emitting layer may be formed of an inorganicmaterial such as a quantum dot.

Hereinafter, a related art electroluminescent display device will bedescribed with reference to FIG. 1.

FIG. 1 is a schematic cross-sectional view of a related art solubleelectroluminescent display device.

As seen in FIG. 1, in the related art soluble electroluminescent displaydevice, a planarization layer 1, an anode electrode 2, a first bank 3, asecond bank 4, a light emitting layer 5, and a cathode electrode 6 aresequentially provided on a substrate (not shown).

The planarization layer 1 planarizes a thin film transistor (TFT) layer(not shown) provided on the substrate, and the anode electrode 2 isprovided on the planarization layer 1.

The first bank 3 and the second bank 4 are provided on the anodeelectrode 2 to define a pixel area. The first bank 3 and the second bank4 are provided on each of one side and the other side of the anodeelectrode 2 to expose an upper surface of the anode electrode 2. Thefirst bank 3 is formed of an inorganic material.

The light emitting layer 5 is provided in the pixel area defined by thefirst bank 3 and the second bank 4, and the cathode electrode 6 isprovided on the light emitting layer 5.

In detail, in the soluble electroluminescent display device, in order toincrease the convenience and efficiency of a manufacturing process, alight emitting material having a soluble characteristic is sprayed ordropped on the pixel area defined by the first and second banks 3 and 4through an inkjet printing process, and then, by curing the lightemitting material, the light emitting layer 5 is formed.

Particularly, in the related art soluble electroluminescent displaydevice, as described above, the bank is formed of a multilayer includingthe first bank 3 and the second bank 4 so as to prevent a pileupphenomenon.

The pileup phenomenon denotes that in a case of spraying a lightemitting material through an inkjet printing process, the light emittinglayer 5 is formed thicker in an edge adjacent to the bank than a centerbetween banks spaced apart from each other. When the light emittinglayer 5 is not planarly formed, luminance non-uniformity occurs in apixel area. For this reason, in the related art, in order to prevent thepileup phenomenon, the bank is formed of a multilayer, and by sprayingthe light emitting material on an upper surface of the first bank 3, thelight emitting layer 5 is planarly formed on an upper surface of theanode electrode 2.

However, the related art soluble electroluminescent display device hasthe following problem.

As described above, the first bank 3 including an inorganic materialshould be deposited through a chemical vapor deposition (CVD) processafter the planarization layer and the TFT layer are formed, but sincethe first bank 3 should be patterned through a dry etching or wetetching process in a process of forming the first bank 3 through the CVDprocess, the anode electrode 2 is damaged in an etching process.

BRIEF SUMMARY

Accordingly, the present disclosure is directed to provide anelectroluminescent display device and a method of manufacturing the samethat substantially obviate one or more problems due to limitations anddisadvantages of the related art.

An aspect of the present disclosure is directed to provide anelectroluminescent display device and a method of manufacturing thesame, in which an anode electrode is prevented from being damaged in aprocess of forming a bank on the anode electrode.

Another aspect of the present disclosure is directed to provide anelectroluminescent display device and a method of manufacturing thesame, in which a light emitting layer is provided on an anode electrodeto have a uniform thickness, for realizing uniform luminance.

Additional advantages and features of the disclosure will be set forthin part in the description which follows and in part will becomeapparent to those having ordinary skill in the art upon examination ofthe following or may be learned from practice of the disclosure. Theobjectives and other advantages of the disclosure may be realized andattained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purposeof the disclosure, as embodied and broadly described herein, there isprovided an electroluminescent display device including a first bank ona substrate, an anode electrode extending to one side and another sideof the first bank in an area exposed by the first bank, a second bank oneach of one side and another side of the anode electrode, a lightemitting layer on an upper surface of the anode electrode exposed by thesecond bank, and a cathode electrode on the light emitting layer.

In another aspect of the present disclosure, there is provided a methodof manufacturing an electroluminescent display device including forminga first bank on a substrate by using an inorganic material, forming ananode electrode to extend to one side and another side of the first bankin an area exposed by the first bank, forming a second bank including anorganic material on each of one side and another side of the anodeelectrode, forming a light emitting layer on an upper surface of theanode electrode exposed by the second bank, and forming a cathodeelectrode on the light emitting layer.

It is to be understood that both the foregoing general description andthe following detailed description of the present disclosure are toprovide examples example and are intended to provide further explanationof the disclosure as claimed.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the disclosure and are incorporated in and constitute apart of this application, illustrate embodiments of the disclosure andtogether with the description serve to explain the principle of thedisclosure. In the drawings:

FIG. 1 is a schematic cross-sectional view of a related art solubleelectroluminescent display device;

FIG. 2 is a cross-sectional view of an electroluminescent display deviceaccording to a first embodiment of the present disclosure;

FIG. 3 is a cross-sectional view of an electroluminescent display deviceaccording to a second embodiment of the present disclosure;

FIGS. 4A to 4F are process cross-sectional views illustrating a methodof manufacturing an electroluminescent display device according to afirst embodiment of the present disclosure; and

FIGS. 5A to 5F are process cross-sectional views illustrating a methodof manufacturing an electroluminescent display device according to asecond embodiment of the present disclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to the example embodiments of thepresent disclosure, examples of which are illustrated in theaccompanying drawings. Wherever possible, the same reference numberswill be used throughout the drawings to refer to the same or like parts.

Advantages and features of the present disclosure, and implementationmethods thereof will be clarified through following embodimentsdescribed with reference to the accompanying drawings. The presentdisclosure may, however, be embodied in different forms and should notbe construed as limited to the embodiments set forth herein. Rather,these embodiments are provided so that this disclosure will be thoroughand complete, and will fully convey the scope of the present disclosureto those skilled in the art. Further, the present disclosure is onlydefined by scopes of claims.

A shape, a size, a ratio, an angle, and a number disclosed in thedrawings for describing embodiments of the present disclosure are merelyan example, and thus, the present disclosure is not limited to theillustrated details. Like reference numerals refer to like elementsthroughout. In the following description, when the detailed descriptionof the relevant known function or configuration is determined tounnecessarily obscure the important point of the present disclosure, thedetailed description will be omitted. In a case where ‘comprise,’‘have,’ and ‘include’ described in the present specification are used,another part may be added unless ‘only˜’ is used. The terms of asingular form may include plural forms unless referred to the contrary.

In construing an element, the element is construed as including an errorrange although there is no explicit description.

In describing a position relationship, for example, when a positionrelation between two parts is described as ‘on˜,’ ‘over˜,’ ‘under˜,’ and‘next˜,’ one or more other parts may be disposed between the two partsunless ‘just’ or ‘direct’ is used.

In describing a time relationship, for example, when the temporal orderis described as ‘after˜,’ ‘subsequent˜,’ ‘next˜,’ and ‘before˜,’ a casewhich is not continuous may be included unless ‘just’ or ‘direct’ isused.

It will be understood that, although the terms “first,” “second,” etc.may be used herein to describe various elements, these elements shouldnot be limited by these terms. These terms are only used to distinguishone element from another. For example, a first element could be termed asecond element, and, similarly, a second element could be termed a firstelement, without departing from the scope of the present disclosure.

Features of various embodiments of the present disclosure may bepartially or overall coupled to or combined with each other, and may bevariously inter-operated with each other and driven technically as thoseskilled in the art can sufficiently understand. The embodiments of thepresent disclosure may be carried out independently from each other, ormay be carried out together in co-dependent relationship.

Hereinafter, example embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings.

FIG. 2 is a cross-sectional view of an electroluminescent display deviceaccording to a first embodiment of the present disclosure.

The electroluminescent display device according to the first embodimentof the present disclosure may be implemented as a top emission type.

As illustrated in FIG. 2, the electroluminescent display deviceaccording to the first embodiment of the present disclosure may includea thin film transistor (TFT) layer T, a passivation layer 165, aplanarization layer 170, a first bank 180, an anode electrode 190, asecond bank 200, a light emitting layer 210, and a cathode electrode 220which are provided on a substrate 100.

The TFT layer T may include an active layer 110, a gate insulation layer120, a gate electrode 130, an interlayer dielectric 140, a sourceelectrode 150, and a drain electrode 160.

The active layer 110 may be formed on the substrate 100 to overlap thegate electrode 130. The active layer 110 may be formed of asilicon-based semiconductor material, or may be formed of an oxide-basedsemiconductor material. Although not shown, a light blocking layer maybe further formed between the substrate 100 and the active layer 110,and in this case, external light incident through a bottom of thesubstrate 100 may be blocked by the light blocking layer, therebypreventing the active layer 110 from being damaged by the externallight.

The gate insulation layer 120 may be formed on the active layer 110. Thegate insulation layer 120 may insulate the active layer 110 from thegate electrode 130. The gate insulation layer 120 may be formed of aninorganic insulating material, for example, silicon oxide (SiOx),silicon nitride (SiNx), or a multilayer thereof, but is not limitedthereto.

The gate electrode 130 may be formed on the gate insulation layer 120.The gate electrode 130 may be formed to overlap the active layer 110with the gate insulation layer 120 therebetween. The gate electrode 130may be formed of a single layer or a multilayer which includes one ofmolybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti),nickel (Ni), neodymium (Nd), and copper (Cu), or an alloy thereof, butis not limited thereto.

The interlayer dielectric 140 may be formed on the gate electrode 130.The interlayer dielectric 140 may be formed of an inorganic insulatingmaterial (for example, silicon oxide (SiOx), silicon nitride (SiNx), ora multilayer thereof) which is the same as that of the gate insulationlayer 120, but is not limited thereto.

The source electrode 150 and the drain electrode 160 may be formed onthe interlayer dielectric 140 to face each other. The gate insulationlayer 120 and the interlayer dielectric 140 may include a first contacthole CH1, exposing one area of the active layer 110, and a secondcontact hole CH2 which exposes the other area of the active layer 110.Accordingly, the source electrode 150 may be connected to the other areaof the active layer 110 through the second contact hole CH2, and thedrain electrode 160 may be connected to the one area of the active layer110 through the first contact hole CH1.

In FIG. 2, the source electrode 150 and the drain electrode 160 areillustrated as a single layer, but are not limited thereto.

For example, the source electrode 150 may include a bottom sourceelectrode (not shown) and a top source electrode (not shown), and thebottom source electrode may be formed between the interlayer dielectric140 and the top source electrode to enhance an adhesive force betweenthe interlayer dielectric 140 and the top source electrode. Also, thebottom source electrode may protect a lower surface of the top sourceelectrode, thereby preventing the lower surface of the top sourceelectrode from being corroded. Therefore, an oxidation rate of thebottom source electrode may be lower than that of the top sourceelectrode. That is, a material of the bottom source electrode may be amaterial having a corrosion resistance which is stronger than that of amaterial of the top source electrode. As described above, the bottomsource electrode may act as an adhesion promotor or an anti-corrosionlayer and may be formed of an alloy (MoTi) of molybdenum (Mo) andtitanium (Ti), but is not limited thereto.

Moreover, the top source electrode may be formed on an upper surface ofthe bottom source electrode. The top source electrode may be formed ofcopper (Cu) which is metal having a low resistance, but is not limitedthereto. The top source electrode may be formed of metal having aresistance which is relatively lower than that of the bottom sourceelectrode. In order to decrease a total resistance of the sourceelectrode 150, a thickness of the top source electrode may be setthicker than that of the bottom source electrode.

Similarly to the source electrode 150, the drain electrode 160 may alsoinclude a bottom drain electrode (not shown) and a top drain electrode(not shown). However, the present embodiment is not limited thereto. Inother embodiments, the source electrode 150 and the drain electrode 160may each be formed of a multilayer including more layers than those of atriple layer.

A structure of the TFT layer T is not limited to a structure shown inthe drawing, and may be variously modified into a structure known tothose skilled in the art. For example, in the drawing, the TFT layer Tis illustrated as having a top gate structure where the gate electrode130 is provided on the active layer 110, but is not limited thereto. Inother embodiments, the TFT layer T may be formed in a bottom gatestructure where the gate electrode 130 is provided under the activelayer 110.

The passivation layer 165 may be formed on the TFT layer T, and in moredetail, may be formed on an upper surface of each of the sourceelectrode 150 and the drain electrode 160. The passivation layer 165 mayprotect the TFT layer T and may be formed of an inorganic insulatingmaterial, for example, silicon oxide (SiOx), silicon nitride (SiNx), ora multilayer thereof, but is not limited thereto.

The planarization layer 170 may be formed on the passivation layer 165.The planarization layer 170 may planarize an upper surface of thesubstrate 100 on which the TFT layer T is provided. The passivationlayer 170 may be formed of an organic insulating material such as acrylresin, epoxy resin, phenolic resin, polyamide resin, polyimide resin,and/or the like, but is not limited thereto.

The first bank 180 may be provided on the planarization layer 170. Thefirst bank 180 may perform a function which enables an edge of the anodeelectrode 190 to have a slope. This will be described below in detail.The first bank 180 may be provided on the planarization layer 170 toexpose a first opening area (or a first O/A) having a predeterminedwidth. When the electroluminescent display device is implemented as abottom emission type, the first opening area may correspond to anemissive area.

A side surface of the first bank 180 may be inclined at a certain anglewith respect to a surface of the substrate 100. In detail, asillustrated in FIG. 2, an included angle “a” between the side surface ofthe first bank 180 and the surface of the substrate 100 may be set to 45degrees or less.

That is, when the side surface of the first bank 180 is providedvertical to the surface of the substrate 100, a leakage of a current canoccur in the side surface of the first bank 180 which is relativelysharply provided, and thus, in an embodiment of the present disclosure,the included angle “a” between the side surface of the first bank 180and the surface of the substrate 100 may be set to 45 degrees or less,thereby preventing a current from being leaked through the first bank180. Since the top surface of planarization layer 170 is parallel to thetop surface of the substrate 100 and is also planar, the side edge offirst bank 180 is an included angle “a” between the side surface of thefirst bank 180 and the surface of the planarization layer 170. This canbe set to 45 degrees or less, as noted. In one embodiment, it is set tobe about 45 degrees; in another embodiment, it is set to be less than 45degrees and greater than 30 degrees; in other embodiments, it can be setto be less than 40 degrees and greater than 25 degrees. In otherembodiments, it may be set to be less than 60 degrees but greater than45 degrees. The selection of the angle maybe based on many factors, oneof which may include a preferred angle to reduce the pileup phenomenon,which has been explained herein.

The first bank 180 may be formed of an inorganic material, for example,silicon oxide (SiOx), silicon nitride (SiNx), or a multilayer thereof,but is not limited thereto. The first bank 180 may be formed of aninorganic material on the planarization layer 170 through a chemicalvapor deposition (CVD) process. Therefore, the first bank 180 may beformed of a thin layer having a thickness of about 500 Å.

The anode electrode 190 may be provided on the planarization layer 170and the first bank 180.

The anode electrode 190 may be provided on the planarization layer 170at the locations exposed by the first bank 180 and extend from one sideto the other side of the first bank 180. The passivation layer 165 andthe planarization layer 170 may include a third contact hole CH3 whichexposes the source electrode 150, and the source electrode 150 may beconnected to the anode electrode 190 through the third contact hole CH3.Therefore, in the first embodiment of the present disclosure, in orderfor the source electrode 150 to be connected to the anode electrode 190through the third contact hole CH3, the first bank 180 may be spacedapart from the third contact hole CH3 without overlapping the thirdcontact hole CH3.

As described above, in the electroluminescent display device accordingto an embodiment of the present disclosure, the first bank 180 may befirst provided on the planarization layer 170, and the anode electrode190 is then provided on the first bank 180. This sequence prevents theanode electrode 190 from being damaged in a process of patterning thefirst bank 180 that includes an inorganic material.

In detail, in those situations in which the anode electrode 190 is firstformed and the first bank 180 including an inorganic material isdeposited on the anode electrode 190, the first bank 180 may be formedthrough a CVD process. Since the first bank 180 should be patternedthrough a dry etching or wet etching process in the above-describedprocess, the anode electrode 190 is likely to be damaged in the etchingprocess.

Therefore, in an embodiment of the present disclosure, the first bank180 may be first formed, and then patterned and etched on theplanarization layer 170 to provide locations in which the planarizationlayer is exposed through the first bank. The anode electrode 190 may beformed on the first bank 180 and on the exposed locations of theplanarization layer 170, thereby preventing the anode electrode 190 frombeing damaged in a process of patterning the first bank 180 including aninorganic material.

The anode electrode 190 may be provided to extend from one side and tothe other side of the first bank 180 as well as an upper surface of theplanarization layer 170. In this case, the side surface of the firstbank 180 may be inclined at an angle of 45 degrees or less with respectto the surface of the substrate 100 when it is etched, and thus, theanode electrode 190 may also be provided on each of the one side and theother side of the first bank 180 to have a slope.

When the electroluminescent display device according to the firstembodiment of the present disclosure is implemented as a top emissiontype, since the anode electrode 190 should reflect light emitted fromthe light emitting layer 210 in an up direction, the anode electrode 190may include a material which has a good in reflectivity. The anodeelectrode 190 may be formed of a multilayer of different metals andmetal alloys that have a good light reflectivity.

For example, the anode electrode 190 may include a bottom anodeelectrode (not shown), a top anode electrode (not shown), and a coveranode electrode (not shown). Namely, the anode 190 maybe comprised oftwo or more layers. The bottom anode electrode may be provided betweenthe planarization layer 170 and the top anode electrode to increase anadhesive force between the planarization layer 170 and the top anodeelectrode. The top anode electrode may be provided between the bottomanode electrode and the cover anode electrode. The top anode electrodemay be formed of metal having a resistance which is relatively lowerthan that of each of the bottom anode electrode and the cover anodeelectrode. In order to decrease a total resistance of the anodeelectrode 190, a thickness of the top anode electrode may be set thickerthan that of each of the bottom anode electrode and the cover anodeelectrode. The cover anode electrode may be provided on the top anodeelectrode. The cover anode electrode may be provided to cover an uppersurface and a side surface of the top anode electrode, therebypreventing the top anode electrode from being corroded. Accordingly, anoxidation rate of the cover anode electrode may be lower than that ofthe top anode electrode. That is, the cover anode electrode may beformed of a material having a corrosion resistance which is strongerthan that of a material of the top anode electrode.

However, the present embodiment is not limited thereto. In otherembodiments, the anode electrode 190 may be formed of a double layer ora multilayer including more layers than those of a quadruple layer.

The second bank 200 may be provided on the anode electrode 190.

The second bank 200 may be provided on each of one side and the other ofthe anode electrode 190 to expose an upper surface of the anodeelectrode 190. Since the second bank 200 is provided to expose the uppersurface of the anode electrode 190, an area on which an image isdisplayed is secured. The second bank 200 may be provided on the anodeelectrode 190 to expose a second opening area (a second O/A) having thepredetermined width. When the electroluminescent display deviceaccording to an embodiment of the present disclosure is implemented asthe top emission type, the second opening area may correspond to anemissive area.

The second opening area exposed by the second bank 200 may be providedwider than the first opening area exposed by the first bank 180. Thatis, when the electroluminescent display device according to anembodiment of the present disclosure is implemented as the top emissiontype, the second opening area may correspond to an emissive area, andthus, the second opening area may be provided wider than the firstopening area, thereby enhancing an aperture ratio.

Moreover, since the second opening area is provided wider than the firstopening area, the electroluminescent display device according to anembodiment of the present disclosure has the following effects.

In detail, if the first opening area is provided wider than the secondopening area than the result may be that the second bank 200 is providedup to the upper surface of the anode electrode 190 provided at locationsthat do not overlie either side of the first bank 180. In this case, inthe anode electrode 190, only that region of the upper surface which isplanar with respect to the substrate may be exposed, and the area ofanode electrode 190 which is inclined by the first bank 180 may becovered by the second bank 200. The light emitting layer 210 may beprovided from the planar upper surface of the anode electrode 190 to aside surface of the second bank 200, and thus, a pileup phenomenonoccurs.

The pileup phenomenon denotes that in a case of forming the lightemitting layer 210 through an inkjet printing process, in performing aprocess where a light emitting material of the light emitting layer 210is sprayed or dropped on the anode electrode 190 and then is dried, thelight emitting material is dried and cured, and then, a thickness of thelight emitting layer 210 provided in an area contacting the second bank200 is thicker than that of the light emitting layer 210 provided on anupper surface of the anode electrode 190, causing a thickness deviation.

As a result, the light emitting layer 210 may be planarly provided in acenter of the second opening area of the anode electrode 190 exposed bythe second bank 200 and may have a cross-sectional surface having athickness which increases progressively closer to a portion adjacent tothe second bank 200. Also, if the light emitting layer 210 is providedon the anode electrode 190 to have a non-uniform thickness, luminancenon-uniformity occurs.

Therefore, in an embodiment of the present disclosure, since the secondopening area is provided wider than the first opening area, the uppersurface of the anode electrode 190 which is provided on each of the oneside and the other side of the first bank 180 has a slope that may beexposed by the second bank 200. Also, the light emitting layer 210 maybe provided on the anode electrode 190 having the slope, therebypreventing the pileup phenomenon.

That is, when the light emitting layer 210 is provided on only theplanar upper surface of the anode electrode 190, the light emittinglayer 210 may be relatively thicker provided in an area adjacent to anend region of the anode electrode 190 and the second bank 200.Therefore, in an embodiment of the present disclosure, a region of theanode electrode 190 having a slope may be exposed, and the lightemitting layer 210 may be provided covering the exposed region, therebydecreasing a thickness deviation of the light emitting layer 210.

The bank 200 may be provided on each side of the anode electrode 190,and thus, a side surface of the anode electrode 190 vulnerable tocorrosion is not exposed to the outside, thereby preventing the sidesurface of the anode electrode 190 from being corroded.

The second bank 200 may be formed of an organic insulating material suchas polyimide resin, acryl resin, benzocyclobutene (BCB), and/or thelike, but is not limited thereto.

Particularly, the second bank 200 according to an embodiment of thepresent disclosure may have the layers below the top region whollyformed of a hydrophilic material, and only an upper surface of thesecond bank 200 may be formed of a hydrophobic material. That is, thelight emitting layer 210 and the cathode electrode 220 may be providedon the anode electrode 190 exposed by the second bank 200, and in thiscase, since the light emitting layer 210 and the cathode electrode 220should be provided to have a uniform thickness on the anode electrode190, in an embodiment of the present disclosure, a side surface of thesecond bank 200 may be formed of a hydrophilic material. Therefore, thelight emitting layer 210 may be provided to extend to only the sidesurface of the second bank 200 without passing by the upper surface ofthe second bank 200, and the light emitting layer 210 may be uniformlyprovided up to the side surface of the second bank 200, whereby thelight emitting layer 210 may be provided to have a uniform thickness inthe second opening area exposed by the second bank 200.

Hereinabove, an area having hydrophobicity is described as the uppersurface of the second bank 200, but the present embodiment is notlimited thereto. In other embodiments, an area corresponding to acertain height from the upper surface of the second bank 200 may includea hydrophobic material, and another area may include a hydrophilicmaterial.

The light emitting layer 210 may be provided on the anode electrode 190.The light emitting layer 210 may be provided on the anode electrode 190exposed by the second bank 200. The light emitting layer 210 may includeat least one organic layer of a hole injecting layer, a holetransporting layer, a light emitting layer, an electron transportinglayer, and an electron injecting layer. A structure of the lightemitting layer 210 may be modified into a structure known to thoseskilled in the art.

In the electroluminescent display device according to an embodiment ofthe present disclosure, since the light emitting layer 210 is providedon the anode electrode 190 having a slope in the second opening areaexposed by the second bank 200, a thickness deviation of the lightemitting layer 210 is reduced, and the pileup phenomenon is prevented.

Particularly, at least one of the hole injecting layer, the holetransporting layer, the light emitting layer, the electron transportinglayer, and the electron injecting layer configuring the light emittinglayer 210 may be formed through a soluble process. For example, the holeinjecting layer, the hole transporting layer, and the light emittinglayer may be formed through the soluble process, and the electrontransporting layer and the electron injecting layer may be formedthrough a vapor deposition process. However, the present embodiment isnot limited thereto.

As described above, the soluble process may be a process where a solubleorganic light emitting material is sprayed on the anode electrode 190through an inkjet printing process, and by curing the soluble organiclight emitting material, the light emitting layer 210 is formed, and isused for increasing the convenience and efficiency of a process ofmanufacturing the organic light emitting display device.

The cathode electrode 220 may be provided on the light emitting layer210. In a case where the electroluminescent display device according toan embodiment of the present disclosure is implemented as the topemission type, since the cathode electrode 220 is provided on a surfacethrough which light is output, the cathode electrode 220 may be formedof a transparent conductive material.

Although not shown, an encapsulation layer may be additionally providedon the cathode electrode 220 to prevent penetration of water. Theencapsulation layer may use various materials known to those skilled inthe art. Also, although not shown, a color filter may be additionallyprovided on the cathode electrode 220 in each of a plurality of pixels,and in this case, the light emitting layer 210 may emit white light.

As described above, the electroluminescent display device according toan embodiment of the present disclosure may be implemented in astructure enabling the top emission type, where the light emitted fromthe light emitting layer 210 is output to the outside through thecathode electrode 220, or the bottom emission type where the lightemitted from the light emitting layer 210 is output to the outsidethrough the anode electrode 190, but is not limited thereto. In otherembodiments, the electroluminescent display device according to anembodiment of the present disclosure may be implemented in a dualemission type.

FIG. 3 is a cross-sectional view of an electroluminescent display deviceaccording to a second embodiment of the present disclosure.

The electroluminescent display device according to the second embodimentof the present disclosure may be implemented as the top emission type orthe bottom emission type.

Except that a position of a contact hole for connecting an anodeelectrode to a TFT layer is changed, the electroluminescent displaydevice according to the second embodiment of the present disclosureillustrated in FIG. 3 is the same as the electroluminescent displaydevice of FIG. 2. Hereinafter, therefore, like reference numerals referto like elements, and only different elements will be described.

As illustrated in FIG. 3, the electroluminescent display deviceaccording to the second embodiment of the present disclosure may includea TFT layer T, a passivation layer 165, a planarization layer 170, afirst bank 180, an anode electrode 190, a second bank 200, a lightemitting layer 210, and a cathode electrode 220 which are provided on asubstrate 100.

The passivation layer 165, the planarization layer 170, and the firstbank 180 may include a third contact hole CH3 which exposes a sourceelectrode 150 of the TFT layer T, and the source electrode 150 may beconnected to the anode electrode 190 through the third contact hole CH3.

In the electroluminescent display device according to the firstembodiment of the present disclosure, the third contact hole CH3 may beprovided in the passivation layer 165 and the planarization layer 170,but in the electroluminescent display device according to the secondembodiment of the present disclosure, the third contact hole CH3 may beprovided to pass through the first bank 180.

Therefore, the electroluminescent display device according to the secondembodiment of the present disclosure may be implemented as the bottomemission type without the reduction in aperture ratio.

In detail, in the electroluminescent display device according to thefirst embodiment of the present disclosure, the anode electrode 190 maybe connected to the source electrode 150 through the third contact holeCH3 which does not pass through the first bank 180. Also, in the bottomemission type, the first opening area exposed by the first bank 180 maycorrespond to an emissive area, and the source electrode 150 may bedisposed to overlap the first opening area in an area where the thirdcontact hole CH3 is provided. Therefore, when the electroluminescentdisplay device according to the first embodiment of the presentdisclosure is implemented as the bottom emission type, an aperture ratiocan be reduced by the TFT layer T. In order to solve such a problem, inthe electroluminescent display device according to the second embodimentof the present disclosure, the anode electrode 190 may be connected tothe source electrode 150 through the third contact hole CH3 passingthrough the first bank 180, and thus, an aperture ratio is not reduceddespite the bottom emission type.

That is, as illustrated in FIG. 3, since the third contact hole CH3 isprovided in the passivation layer 165, the planarization layer 170, andthe first bank 180, the first opening area exposed by the first bank 180may not overlap the TFT layer T. Therefore, although theelectroluminescent display device according to the second embodiment ofthe present disclosure is implemented as one of the top emission typeand the bottom emission type, an aperture ratio is not reduced.

Moreover, in the electroluminescent display device according to thesecond embodiment of the present disclosure, the third contact hole CH3may be provided to pass through the first bank 180, and thus, thefollowing effects are obtained.

In detail, even in the electroluminescent display device according tothe second embodiment of the present disclosure, the second opening areaexposed by the second bank 200 may be provided wider than the firstopening area exposed by the first bank 180. Therefore, an upper surfaceof the anode electrode 190 which is provided on each side of the side ofthe first bank 180 and has a slope that may be exposed by the secondbank 200, thereby preventing the pileup phenomenon.

Particularly, when the electroluminescent display device according tothe second embodiment of the present disclosure is implemented as thetop emission type, as described above with reference to FIG. 2, athickness deviation of the light emitting layer 210 provided on theanode electrode 190 is reduced. Also, when the electroluminescentdisplay device according to the second embodiment of the presentdisclosure is implemented as the bottom emission type, since theemissive area corresponds to the first opening area, the light emittinglayer 210 provided on the anode electrode 190 in the first opening areamay be more planarly provided than the light emitting layer 210 providedon the anode electrode 190 in the second opening area. Accordingly, whenthe electroluminescent display device according to the second embodimentof the present disclosure is implemented as the bottom emission type,the light emitting layer 210 provided on an upper surface of the anodeelectrode 190 may have a uniform thickness, thereby realizing uniformluminance.

As described above, in the electroluminescent display device accordingto the second embodiment of the present disclosure, the anode electrode190 may be connected to the source electrode 150 through the thirdcontact hole CH3 which is provided to pass through the first bank 180 aswell as the passivation layer 165 and the planarization layer 170.Accordingly, even when the electroluminescent display device accordingto the second embodiment of the present disclosure is implemented as thebottom emission type, an aperture ratio is not reduced.

In a case where the electroluminescent display device according to thesecond embodiment of the present disclosure is implemented as the topemission type, since the anode electrode 190 should reflect lightemitted from the light emitting layer 210 in an up direction, the anodeelectrode 190 may include a material which is good in reflectivity. Onthe other hand, when the electroluminescent display device according tothe second embodiment of the present disclosure is implemented as thebottom emission type, the anode electrode 190 may be provided on asurface through which light is output, the anode electrode 190 may beformed of a transparent conductive material such as indium tin oxide(ITO).

When the electroluminescent display device according to the secondembodiment of the present disclosure is implemented as the top emissiontype, the cathode electrode 220 may be provided on a surface throughwhich light is output, and thus, the cathode electrode 220 may be formedof a transparent conductive material. On the other hand, in a case wherethe electroluminescent display device according to the second embodimentof the present disclosure is implemented as the bottom emission type,since the cathode electrode 220 should reflect the light emitted fromthe light emitting layer 210 in a down direction, the cathode electrode220 may include a material which is good in reflectivity.

Moreover, in the electroluminescent display device according to thesecond embodiment of the present disclosure, the second opening area maybe provided wider than the first opening area, and thus, the lightemitting layer 210 may be provided from an area where the anodeelectrode 190 has a slope, thereby decreasing a thickness deviation ofthe light emitting layer 210 in the emissive area and realizing uniformluminance.

FIGS. 4A to 4F are process cross-sectional views illustrating a methodof manufacturing an electroluminescent display device according to afirst embodiment of the present disclosure and relate to a method ofmanufacturing the electroluminescent display device of FIG. 2.Hereinafter, therefore, like reference numerals refer to like elementsthroughout, and in a material and a structure of each element,repetitive descriptions are omitted.

First, as seen in FIG. 4A, an active layer 110, a gate insulation layer120, a gate electrode 130, an interlayer dielectric 140, a sourceelectrode 150, and a drain electrode 160 may be sequentially formed on asubstrate 100.

To provide a more detailed description, the active layer 110 may beformed on the substrate 100, the gate insulation layer 120 may be formedon the active layer 110, the gate electrode 130 may be formed on thegate insulation layer 120, the interlayer dielectric 140 may be formedon the gate electrode 130, a first contact hole CH1 and a second contacthole CH2 may be formed in the gate insulation layer 120 and theinterlayer dielectric 140, and the drain electrode 160 connected to onearea of the active layer 110 through the first contact hole CH1 and thesource electrode 150 connected to the other area of the active layer 110through the second contact hole CH2 may be formed.

The source electrode 150 and the drain electrode 160 may each be formedof a multilayer. The source electrode 150 and the drain electrode 160may be simultaneously formed of the same material through the samepatterning process.

Subsequently, as seen in FIG. 4B, a passivation layer 165 may be formedon the source electrode 150 and the drain electrode 160, and aplanarization layer 170 may be formed on the passivation layer 165.

The passivation layer 165 and the planarization layer 170 may be formedto have a third contact hole CH3, and thus, the source electrode 150 maybe exposed to the outside through the third contact hole CH3.

Subsequently, as seen in FIG. 4C, a first bank 180 may be formed on theplanarization layer 170. The first bank 180 may be patterned on theplanarization layer 170 to expose a predetermined first opening area (ora first O/A). The first bank 180 may be patterned and etch so that whenit is completely formed it does not overlap the third contact hole CH3and may be spaced apart from the third contact hole CH3.

A side surface of the first bank 180 may be inclined at a certain anglewith respect to a surface of the substrate 100. In detail, an includedangle “a” between the side surface of the first bank 180 and the surfaceof the substrate 100 may be set to 45 degrees or less.

The side surface of the first bank 180 may be formed so as to beinclined at a certain angle by using various technologies known to thoseskilled in the art. For example, by using a halftone mask or a slitmask, the first bank 180 may be formed in order for a thickness thereofto be progressively thinned in an edge thereof, and moreover, may beformed to have a constant thickness in an area other than the edge, butthe present embodiment is not limited thereto.

The first bank 180 may be formed of an inorganic material, for example,silicon oxide (SiOx), silicon nitride (SiNx), or a multilayer thereof,but is not limited thereto. The first bank 180 may be formed on theplanarization layer 170 through a CVD process. Therefore, the first bank180 may be formed of a thin layer having a thickness of about 500 Å.

Subsequently, as seen in FIG. 4D, an anode electrode 190 may be formedon the first bank 180. The anode electrode 190 may be formed on theplanarization layer 170 exposed by the first bank 180 to extend to oneside and the other side of the first bank 180. A side surface of thefirst bank 180 may be formed to have a certain slope, and thus, an areahaving a certain slope may be formed in an edge of the anode electrode190 formed on each of the one side and the other side of the first bank180. The anode electrode 190 may be formed so as to be connected to thesource electrode 150 through the third contact hole CH3 which is formedin the passivation layer 165 and the planarization layer 170.

Subsequently, as seen in FIG. 4E, a second bank 200 including an organicmaterial may be formed on the anode electrode 190. In detail, the secondbank 200 may be formed on each of one side and the other side of theanode electrode 190 to expose an upper surface of the anode electrode190. The second bank 200 may be patterned to expose a predeterminedsecond opening area (or a second O/A). The second opening area exposedby the second bank 200 may be formed wider than the first opening areaexposed by the first bank 180.

In detail, when the first opening area is formed wider than the secondopening area, only an upper surface of the anode electrode 190 which isplanar with respect to the substrate may be exposed, and a region of theanode electrode 190 which is inclined by the first bank 180 may becovered by the second bank 200. Also, a light emitting layer 210 may beformed from the planar upper surface of the anode electrode 190 to aside surface of the second bank 200 through a below-described process,and for this reason, the pileup phenomenon occurs. That is, the lightemitting layer 210 may be planarly provided in a center of the secondopening area of the anode electrode 190 exposed by the second bank 200and may have a cross-sectional surface having a thickness whichincreases progressively closer to a portion adjacent to the second bank200. Also, if the light emitting layer 210 is provided on the anodeelectrode 190 to have a non-uniform thickness, luminance non-uniformityoccurs.

Therefore, in an embodiment of the present disclosure, since the secondopening area is provided wider than the first opening area, the uppersurface of the anode electrode 190 which is provided on each of the oneside and the other side of the first bank 180 and has a slope may beexposed by the second bank 200. Also, the light emitting layer 210 maybe provided on the anode electrode 190 having the slope, therebypreventing the pileup phenomenon.

That is, when the light emitting layer 210 is provided on only theplanar upper surface of the anode electrode 190, the light emittinglayer 210 may be relatively thicker provided in an area adjacent to theanode electrode 190 and the second bank 200. Therefore, in an embodimentof the present disclosure, a region of the anode electrode 190 having aslope may be exposed, and the light emitting layer 210 may be providedfrom the exposed region, thereby decreasing a thickness deviation of thelight emitting layer 210.

A process of patterning the second bank 200 on the one side and theother side of the anode electrode 190 may use a photolithographyprocess, and the second bank 200 may be patterned through varioustechnologies known to those skilled in the art.

In a process of forming the second bank 200 on the anode electrode 190,hydrophobic treatment may be performed on the second bank 200 in orderfor an upper surface of the second bank 200 to have hydrophobicity. Amethod of performing the hydrophobic treatment on the upper surface ofthe second bank 200 may use various technologies known to those skilledin the art. For example, in a process of patterning the second bank 200with a mask, the hydrophobic treatment may be performed on the uppersurface of the second bank 200 by adjusting a degree of exposureperformed on the second bank 200, or by using a coating apparatus suchas a roller with a hydrophobic material coated thereon, the hydrophobicmaterial may be coated on the upper surface of the second bank 200.However, the present embodiment is not limited thereto.

Subsequently, as seen in FIG. 4F, the light emitting layer 210 and acathode electrode 220 may be sequentially formed on the anode electrode190. The light emitting layer 210 may be formed by spraying a solublelight emitting material through the inkjet printing process, and asdescribed above, the upper surface of the second bank 200 may be formedof a hydrophobic material. Accordingly, the light emitting layer 210 maybe deposited up to the upper surface of the anode electrode 190 and aside surface of the second bank 200, but is not deposited on the uppersurface of the second bank 200.

That is, in an embodiment of the present disclosure, the second bank 200may be wholly formed of a hydrophilic material, and only the uppersurface of the second bank 200 may be formed of a hydrophobic material,thereby preventing the light emitting layer 210 from being distributedto an emissive area of another pixel other than the upper surface of thesecond bank 200.

Moreover, in an embodiment of the present disclosure, the anodeelectrode 190 may be formed on each of one side and the other side ofthe first bank 180, and thus, an inclined area may be formed in an edgeof the anode electrode 190. Also, the second opening area exposed by thesecond bank 200 may be formed wider than the first opening area exposedby the first bank 180. Therefore, the light emitting layer 210 may beformed up to an upper surface of the inclined area of the anodeelectrode 190, thereby reducing a thickness deviation of the lightemitting layer 210.

Moreover, in an embodiment of the present disclosure, since the firstbank 180 is formed before forming the anode electrode 190, the anodeelectrode 190 is prevented from being damaged in a process of dryetching or wet etching the first bank 180 including an inorganicmaterial.

FIGS. 5A to 5F are process cross-sectional views illustrating a methodof manufacturing an electroluminescent display device according to asecond embodiment of the present disclosure and relate to a method ofmanufacturing the electroluminescent display device of FIG. 3.Hereinafter, therefore, like reference numerals refer to like elementsthroughout, and in a material and a structure of each element,repetitive descriptions are omitted.

First, as seen in FIG. 5A, an active layer 110, a gate insulation layer120, a gate electrode 130, an interlayer dielectric 140, a sourceelectrode 150, and a drain electrode 160 may be sequentially formed on asubstrate 100.

To provide a more detailed description, the active layer 110 may beformed on the substrate 100, the gate insulation layer 120 may be formedon the active layer 110, the gate electrode 130 may be formed on thegate insulation layer 120, the interlayer dielectric 140 may be formedon the gate electrode 130, a first contact hole CH1 and a second contacthole CH2 may be formed in the gate insulation layer 120 and theinterlayer dielectric 140, and the drain electrode 160 connected to onearea of the active layer 110 through the first contact hole CH1 and thesource electrode 150 connected to the other area of the active layer 110through the second contact hole CH2 may be formed.

The source electrode 150 and the drain electrode 160 may each be formedof a multilayer. The source electrode 150 and the drain electrode 160may be simultaneously formed of the same material through the samepatterning process.

Subsequently, as seen in FIG. 5B, a passivation layer 165 may be formedon the source electrode 150 and the drain electrode 160, and aplanarization layer 170 may be formed on the passivation layer 165.

Subsequently, as seen in FIG. 5C, a first bank 180 may be formed on theplanarization layer 170. The first bank 180 may be patterned on theplanarization layer 170 to expose a predetermined first opening area (ora first O/A). The first bank 180 may be formed to have a third contacthole CH3 and may be exposed to the outside through the third contacthole CH3.

A side surface of the first bank 180 may be inclined at a certain anglewith respect to a surface of the substrate 100. In detail, an includedangle “a” between the side surface of the first bank 180 and the surfaceof the substrate 100 may be set to 45 degrees or less.

The side surface of the first bank 180 may be formed so as to beinclined at a certain angle by using various technologies known to thoseskilled in the art. For example, by using a halftone mask or a slitmask, the first bank 180 may be formed in order for a thickness thereofto be progressively thinned in an edge thereof, and moreover, may beformed to have a constant thickness in an area other than the edge, butthe present embodiment is not limited thereto.

The first bank 180 may be formed of an inorganic material, for example,silicon oxide (SiOx), silicon nitride (SiNx), or a multilayer thereof,but is not limited thereto. The first bank 180 may be formed on theplanarization layer 170 through a CVD process. Therefore, the first bank180 may be formed of a thin layer having a thickness of about 500 Å.

Subsequently, as seen in FIG. 5D, an anode electrode 190 may be formedon the first bank 180. The anode electrode 190 may be formed on theplanarization layer 170 exposed by the first bank 180 to extend to oneside and the other side of the first bank 180. A side surface of thefirst bank 180 may be formed to have a certain slope, and thus, an areahaving a certain slope may be formed in an edge of the anode electrode190 formed on each of the one side and the other side of the first bank180. The anode electrode 190 may be formed so as to be connected to thesource electrode 150 through the third contact hole CH3 which is formedin the passivation layer 165, the planarization layer 170, and the firstbank 180.

Subsequently, as seen in FIG. 5E, a second bank 200 including an organicmaterial may be formed on the anode electrode 190. In detail, the secondbank 200 may be formed on each of one side and the other side of theanode electrode 190 to expose an upper surface of the anode electrode190. The second bank 200 may be patterned to expose a predeterminedsecond opening area (or a second O/A). The second opening area exposedby the second bank 200 may be formed wider than the first opening areaexposed by the first bank 180.

That is, in an embodiment of the present disclosure, since the secondopening area is formed wider than the first opening area, a region ofthe anode electrode 190 having a slope may be exposed, and thus, thelight emitting layer 210 may be formed from the exposed region through abelow-described process, thereby decreasing a thickness deviation of thelight emitting layer 210.

A process of patterning the second bank 200 on the one side and theother side of the anode electrode 190 may use a photolithographyprocess, and the second bank 200 may be patterned through varioustechnologies known to those skilled in the art.

In a process of forming the second bank 200 on the anode electrode 190,hydrophobic treatment may be performed on the second bank 200 in orderfor an upper surface of the second bank 200 to have hydrophobicity. Amethod of performing the hydrophobic treatment on the upper surface ofthe second bank 200 may use various technologies known to those skilledin the art. For example, in a process of patterning the second bank 200with a mask, the hydrophobic treatment may be performed on the uppersurface of the second bank 200 by adjusting a degree of exposureperformed on the second bank 200, or by using a coating apparatus suchas a roller with a hydrophobic material coated thereon, the hydrophobicmaterial may be coated on the upper surface of the second bank 200.However, the present embodiment is not limited thereto.

Subsequently, as seen in FIG. 5F, the light emitting layer 210 and acathode electrode 220 may be sequentially formed on the anode electrode190. The light emitting layer 210 may be formed by spraying a solublelight emitting material through the inkjet printing process, and asdescribed above, the upper surface of the second bank 200 may be formedof a hydrophobic material. Accordingly, the light emitting layer 210 maybe deposited up to the upper surface of the anode electrode 190 and aside surface of the second bank 200, but is not deposited on the uppersurface of the second bank 200.

That is, in an embodiment of the present disclosure, the second bank 200may be wholly formed of a hydrophilic material, and only the uppersurface of the second bank 200 may be formed of a hydrophobic material,thereby preventing the light emitting layer 210 from being distributedto an emissive area of another pixel other than the upper surface of thesecond bank 200.

Moreover, in an embodiment of the present disclosure, the anodeelectrode 190 may be formed on each of one side and the other side ofthe first bank 180, and thus, an inclined area may be formed in an edgeof the anode electrode 190. Also, the second opening area exposed by thesecond bank 200 may be formed wider than the first opening area exposedby the first bank 180. Therefore, the light emitting layer 210 may beformed up to an upper surface of the inclined area of the anodeelectrode 190, thereby reducing a thickness deviation of the lightemitting layer 210.

Moreover, in an embodiment of the present disclosure, since the firstbank 180 is formed before forming the anode electrode 190, the anodeelectrode 190 is prevented from being damaged in a process of dryetching or wet etching the first bank 180 including an inorganicmaterial.

As described above, according to the embodiments of the presentdisclosure, the first bank may be formed of an inorganic material, andthe anode electrode may be provided on the first bank, therebypreventing the anode electrode from being damaged in a process offorming the first bank.

Moreover, according to the embodiments of the present disclosure, a sidesurface of the first bank may be inclined at a certain angle withrespect to a surface of the substrate, thereby preventing a leakagecurrent from occurring in a side surface of the first bank.

Moreover, according to the embodiments of the present disclosure, theanode electrode may be connected to the source electrode through thecontact hole passing through the first bank, and thus, even when theelectroluminescent display device is implemented as the bottom emissiontype, an aperture ratio is maintained.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present disclosurewithout departing from the spirit or scope of the disclosures. Thus, itis intended that the present disclosure covers the modifications andvariations of this disclosure provided they come within the scope of theappended claims and their equivalents.

The various embodiments described above can be combined to providefurther embodiments. All of the U.S. patents, U.S. patent applicationpublications, U.S. patent applications, foreign patents, foreign patentapplications and non-patent publications referred to in thisspecification and/or listed in the Application Data Sheet areincorporated herein by reference, in their entirety. Aspects of theembodiments can be modified, if necessary to employ concepts of thevarious patents, applications and publications to provide yet furtherembodiments.

These and other changes can be made to the embodiments in light of theabove-detailed description. In general, in the following claims, theterms used should not be construed to limit the claims to the specificembodiments disclosed in the specification and the claims, but should beconstrued to include all possible embodiments along with the full scopeof equivalents to which such claims are entitled. Accordingly, theclaims are not limited by the disclosure.

What is claimed is:
 1. An electroluminescent display device, comprising:a first bank on a substrate; an anode electrode extending from one sideto the other side of the first bank to overlay a portion of the firstbank on each side and also an area of the substrate exposed by the firstbank; a second bank positioned to overlay a first side and a second sideof the anode electrode; a light emitting layer on an upper surface ofthe anode electrode that is exposed by the second bank; and a cathodeelectrode on the light emitting layer.
 2. The electroluminescent displaydevice of claim 1, wherein the first bank is provided to expose a firstopening area on the substrate, the second bank is provided to expose asecond opening area on the anode electrode, and the second opening areais provided wider than the first opening area.
 3. The electroluminescentdisplay device of claim 1, wherein the first bank comprises an inorganicmaterial, and an upper surface of the second bank comprises an organicmaterial having hydrophobicity.
 4. The electroluminescent display deviceof claim 1, wherein a side surface of the first bank is inclined at acertain angle with respect to a surface of the substrate.
 5. Theelectroluminescent display device of claim 1, further comprising: a thinfilm transistor on the substrate; and a planarization layer on the thinfilm transistor, wherein the first bank is provided on the planarizationlayer.
 6. The electroluminescent display device of claim 5, wherein theanode electrode is connected to the thin film transistor through acontact hole provided in the planarization layer.
 7. Theelectroluminescent display device of claim 6, wherein the first bank isspaced apart from the contact hole and the anode electrode does not passthrough the first bank.
 8. The electroluminescent display device ofclaim 2, wherein the anode electrode is connected to the thin filmtransistor through a contact hole which is provided in the planarizationlayer and the first bank and the anode electrode overlays a portion ofthe first bank that is located between the contact hole and the firstopening area.
 9. The electroluminescent display device of claim 1,wherein an end region of the first bank that is overlaid by the anodehas a slope of a selected angle.
 10. The electroluminescent displaydevice of claim 9, wherein the selected angle is about 45°.
 11. Theelectroluminescent display device of claim 9, wherein the selected angleis less than 45° and greater than 30°.
 12. The electroluminescentdisplay device of claim 9, wherein the selected angle is less than 40°and greater than 25°
 13. A method of manufacturing an electroluminescentdisplay device, the method comprising: forming a first bank on asubstrate by using an inorganic material; forming an anode electrodethat extends from one side to another side of the first bank in an areaon the substrate exposed by the first bank; forming a second bankincluding an organic material on each a first side and a second side ofthe anode electrode; forming a light emitting layer on an upper surfaceof the anode electrode exposed by the second bank; and forming a cathodeelectrode on the light emitting layer.
 14. The method of claim 13,further comprising: before the forming of the first bank, forming a thinfilm transistor on the substrate; and forming a planarization layer onthe thin film transistor.
 15. The method of claim 14, furthercomprising: before the forming of the anode electrode, removing aselected region of the planarization layer to form a contact hole whichexposes the thin film transistor, connecting the anode electrode to thethin film transistor through the contact hole.
 16. The method of claim14, further comprising: before the forming of the anode electrode,removing a certain region of each of the planarization layer and thefirst bank to form a contact hole which exposes the thin filmtransistor, connecting the anode electrode to the thin film transistorthrough the contact hole.
 17. The method according to claim 13 the stepof forming the second bank comprises: depositing the blanket layer ofmaterial; etching away a portion of the second bank to form an exposedarea of the anode electrode.
 18. The method according to claim 13wherein the exposed area of the anode electrode is wider than the areaof the substrate exposed by the first bank.
 19. The method according toclaim 14 wherein the substrate is a planarization layer that overliesthe transistor.